The people of Palau -- a pristine ocean state made up of more than 300 islands in the western Pacific -- warmly welcome travelers to their home every year. But the guests don't always know how to protect the country's beautiful beaches and coral atolls. Enter the Palau Pledge: an environmental pledge that's now part of visitors' visas, where they promise to "tread lightly, act kindly and explore mindfully" -- while respecting the country's culture and heritage. (Thanks to Jennifer Koskelin-Gibbons and Susan Kloulechad)